Configure reComputer R1100

Overview

Learn how to configure and test hardware components on the reComputer R1100 series after installing devices. This wiki covers GPIO mapping, USER LED testing, SPI communication, Wi-Fi and Bluetooth scanning, LoRa®, 4G, Zigbee over Mini-PCIe, RS485, RS232, DI/DO testing,UPS for safe shutdown and more.

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Query GPIO Mappings and Offsets

To check GPIO mappings and offsets, follow these steps:

• Run the following command in the terminal

cat /sys/kernel/debug/gpio

This command will display GPIO mappings and offsets, providing essential information for debugging or configuring GPIO pins.

Control LED Indicators

The reComputer R1100 provides three LED indicators in red, blue, and green. You can control them using the following commands:

1. Navigate to the LED directory

cd /sys/class/leds/
ls

This will list the available LEDs.

2. Enable LEDs by writing to the brightness file
Switch to superuser mode first:

sudo su

Then, turn on the LEDs:

echo 1 > /sys/class/leds/led-red/brightness
echo 1 > /sys/class/leds/led-blue/brightness
echo 1 > /sys/class/leds/led-green/brightness

This will light up the corresponding LED.

3. Turn off LEDs (optional)
To turn off a specific LED, use:

echo 0 > /sys/class/leds/led-red/brightness
echo 0 > /sys/class/leds/led-blue/brightness
echo 0 > /sys/class/leds/led-green/brightness

Testing SPI Communication

To verify SPI communication, you can perform a loopback test by shorting the TPM module's MISO and MOSI pins. This method ensures that data sent on MOSI (Master Out, Slave In) is received on MISO (Master In, Slave Out).

Step-by-Step Guide

1. Connect to the Internet
Make sure your device is connected to a network before proceeding.

2. Clone the spidev-test repository

git clone https://github.com/rm-hull/spidev-test.git

3. Navigate into the directory

cd spidev-test

4. Compile the spidev_test.c program

gcc spidev_test.c -o spidev_test

5. Run the SPI test

./spidev_test -D /dev/spidev0.1 -v -p "hello"

• -D /dev/spidev0.1 → Specifies the SPI device
• -v → Enables verbose output
• -p "hello" → Sends the string "hello"

6. Loopback Test (Optional)

• Short the TPM module's MISO and MOSI pins before running the test.
• If the SPI bus is functioning correctly, the output should show the transmitted data being received correctly.

Wi-Fi Scanning

To list available Wi-Fi networks and their details, run:

sudo iwlist wlan0 scan

• This command scans for all nearby Wi-Fi networks and displays their SSIDs, signal strength, and encryption type.

Bluetooth Scanning

To scan for Bluetooth devices, follow these steps:

Open the Bluetooth control interface:

sudo bluetoothctl

Enable scanning:

scan on

• This starts scanning for nearby Bluetooth devices.

LoRa® over Mini-PCIe

LoRa® SPI Configuration

Clone the SX1302_HAL repository:

cd ~
git clone https://github.com/Lora-net/sx1302_hal

Navigate to the cloned directory:

cd sx1302_hal

Modify the configuration file:

Open the I2C device configuration file:

sudo vim ./libloragw/inc/loragw_i2c.h

Change this line:

#define I2C_DEVICE "/dev/i2c-1"

To:

#define I2C_DEVICE "/dev/i2c-3"

Compile the code:

sudo make

Modify the reset script:

Open the reset_lgw.sh script:

sudo vim ./tools/reset_lgw.sh

Update the pin configurations:

SX1302_RESET_PIN=580    # SX1302 reset  
SX1302_POWER_EN_PIN=578 # SX1302 power enable  
SX1261_RESET_PIN=579    # SX1261 reset (LBT/Spectral Scan)  

Copy the reset script to the packet forwarder directory:

cp ~/sx1302_hal/tools/reset_lgw.sh ~/sx1302_hal/packet_forwarder/

Update the default SPI port in the LoRaWAN® configuration file:

Modify the global_conf.json.sx1250.US915 file:

sed -i 's/spidev0.0/spidev0.1/g' global_conf.json.sx1250.US915

Start the LoRaWAN® module:

cd ~/sx1302_hal/packet_forwarder
sudo ./lora_pkt_fwd -c global_conf.json.sx1250.US915

LoRa® USB Configuration

If you are using a LoRa® USB module instead of LoRa® SPI, follow these steps. Most commands remain the same as for LoRa® SPI, except for the final step.

Pull up the SX1302 Reset Pin

echo 1 > /sys/class/gpio/gpio580/value

Start the LoRaWAN® USB module

cd ~/sx1302_hal/packet_forwarder
sudo ./lora_pkt_fwd -c global_conf.json.sx1250.EU868.USB

LoRa® USB is now configured and running on reComputer R1100

4G Cellular over Mini-PCIe

To interact with a 4G module using AT commands via minicom, follow these steps:

Open Minicom with the appropriate serial port and baud rate:

sudo minicom -D /dev/ttyUSB2 -b 115200

This command opens Minicom with the specified serial port (/dev/ttyUSB2) at a baud rate of 115200.

Send AT commands to the 4G module:

Once Minicom is open, you can start sending AT commands to the 4G module. For example:

AT

This command checks if the module is responsive. If the module is working properly, you should receive an "OK" response.

Dial a phone number using the 4G module:

To dial a phone number, use the ATD command followed by the phone number:

ATD<phone_number>;

• Replace <phone_number> with the desired phone number you want to dial.
• Make sure to include a semicolon (;) at the end of the command to indicate the end of the phone number.

Here’s the corrected and well-structured version with improved grammar, readability, and formatting:

Zigbee over Mini-PCIe

To test Zigbee communication between two Zigbee modules, follow these steps:

Check Available Serial Ports

Run the following command to check the available serial ports:

cat /dev/ttyUSB*

Install a Serial Communication Tool

Install CuteCom, a graphical serial terminal, using:

sudo apt-get install cutecom

Configure the First Zigbee Module (Coordinator)

• Open CuteCom and configure it for the first serial port.
• Settings:
  • Baud Rate: 115200
  • Enable "Hex output" at the bottom of the interface.

Steps to Configure as a Coordinator:

1. Set as Coordinator: Send command:

   55 04 00 05 00 05  
   • Expected response:

   55 04 00 05 00 05  
2. Reset Device:
   • Press the reset button, or
   • Send command:

     55 07 00 04 00 FF FF 00 04  
3. Network Formation:
   • Send command:

   55 03 00 02 02  

Configure the Second Zigbee Module (Router)

• Open another instance of CuteCom and configure it for the second serial port using the same settings.

Steps to Configure as a Router:

1. Set as Router: Send command:

   55 04 00 05 01 04  
   • Expected response:

   55 04 00 05 00 05  
2. Reset Device:
   • Press the reset button, or
   • Send command:

     55 07 00 04 00 FF FF 00 04  
3. Network Formation: Send command:

   55 03 00 02 02  

Check Device Status
To verify the device status, send:

55 03 00 00 00  

Expected response:

55 2A 00 00 00 01 XX XX XX XX  

• XX represents device-specific information.

Enter Transparent Mode

If network formation is successful, enable transparent mode by sending:

55 07 00 11 00 03 00 01 13  

Both modules must be in transparent mode for direct communication.
To exit transparent mode, send:

+++  

Additional Notes

• If router configuration fails, the device may already be a coordinator. To leave the network, send:

  55 07 00 04 02 XXXX XX  
• To test transmission power, use:
  • Query power:

    55 04 0D 00 00 0D  
  • Set power:

    55 04 0D 01 XXXX  

Ensure you replace /dev/ttyUSB* with the correct serial port for each Zigbee module.
Follow these steps carefully to establish successful Zigbee communication between the two modules.

Here’s the corrected and well-structured version with improved grammar, readability, and formatting:

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RS485 Testing

The reComputer R1100 includes two RS485 ports. Below are their corresponding COM ports and device files:

RS485 Port	COM Port	Silkscreen Label	Device File
RS485_1	COM1	A1 / B1 / GND	/dev/ttyACM0
RS485_2	COM2	A2 / B2 / GND	/dev/ttyACM1

Steps to Test RS485 Functionality

Connect the RS485 Ports

Physically connect RS485_1 (A & B) to RS485_2 (A & B).

Run the RS485 Test Program

We provide a test program to verify data transmission and measure the speed between the two RS485 ports.

Run the following commands to download and execute the test program:

git clone https://github.com/ackPeng/R1100_TEST.git
cd R1100_TEST
gcc -o serial_test serial_test.c
./serial_test /dev/ttyACM0 /dev/ttyACM1 115200

Test Description

• This program sends 1MB of data from RS485_1 to RS485_2.
• It records the completion time and calculates the actual baud rate.
• Note: The actual baud rate may be slightly lower than the theoretical baud rate, which is expected.

Follow these steps carefully to verify RS485 communication on reComputer R1100.

RS232 Testing

The reComputer R1100 features two RS232 ports. Below are the corresponding COM ports and device files:

RS232 Port	COM Port	Pin Mapping	Device File
RS232_1	COM3	RX3/TX3/GND	/dev/ttyACM2
RS232_2	COM4	RX4/TX4/GND	/dev/ttyACM3

Testing RS232 Communication

Follow these steps to test RS232 functionality:

1. Connect the ports:

   • Connect TX of RS232_1 to RX of RS232_2.
   • Connect RX of RS232_1 to TX of RS232_2.

2. Run the test program:

   • Clone the test program repository:

     git clone https://github.com/ackPeng/R1100_TEST.git
   • Navigate to the directory:

     cd R1100_TEST
   • Compile the test program:

     gcc -o serial_test serial_test.c
   • Run the test:

     ./serial_test /dev/ttyACM2 /dev/ttyACM3 115200

This test sends 1MB of data from RS232_1 to RS232_2 and measures the completion time and baud rate. Note that the actual baud rate may be slightly lower than the theoretical value, which is normal.

DI (Digital Input) Testing

The reComputer R1100 includes two Digital Input (DI) ports, which can be configured based on user requirements.

Number of DI Ports	DI Port	Corresponding Extended GPIO
2	DI1	GPIO530
	DI2	GPIO531

DI Port Specifications

• Input Type: PNP
• Supported Input Voltage: 5VDC – 24VDC
• Current: Up to 1000mA

Steps to Test DI Functionality

Ensure Proper Connection

Make sure the DI port of the reComputer R1100 is properly connected to the external load, also make sure that the G_D port is connected to the power supply GND.

Check the GPIO Status

Run the following commands to check the status of GPIO530 (corresponding to DI1):

echo 530 > /sys/class/gpio/export
echo in > /sys/class/gpio/gpio530/direction
cat /sys/class/gpio/gpio530/value

Interpret the GPIO Value

• If the external level is HIGH, the output of /sys/class/gpio/gpio530/value will be 0.
• If the external level is LOW, the output of /sys/class/gpio/gpio530/value will be 1.

DO (Digital Output)

The reComputer R1100 includes two Digital Output (DO) ports, which can be configured based on user requirements.

Number of DO Ports	DO Port	Corresponding Extended GPIO
2	DO1	GPIO532
	DO2	GPIO533

DO Port Specifications

• Output Type: Transistor
• Supported Output Voltage: Up to 60VDC
• Current Capacity: 500mA

Steps to Test DO Functionality

Ensure Proper Connection
Confirm that the DO port of the reComputer R1100 is properly connected to the external load.

Since the DO port is an open collector output and has no drive capability, please use an external resistor to pull it up to the power supply.

Set the Output Level
Run the following commands to set the output to HIGH or LOW:

echo 532 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio532/direction
echo 1 > /sys/class/gpio/gpio532/value  # Set output to HIGH
echo 0 > /sys/class/gpio/gpio532/value  # Set output to LOW

USB Hub Testing

To verify the functionality of the USB hub, follow these steps:

Check if the USB Hub is Detected

Run the following command to list all connected USB devices, including hubs:

lsusb

Verify USB Hub Detection

• This command will display information about all USB devices connected to your system, including USB hubs.
• If the USB hub is functioning properly, its details should appear in the command output.
• If the hub is not listed, there may be an issue with the hub itself or its connection to the system.

Troubleshooting (If the USB Hub is Not Detected)

• Check the physical connection of the USB hub.
• Try connecting the hub to a different USB port.
• Restart the device and rerun lsusb.
• If the issue persists, the hub may be faulty.

RTC (Real-Time Clock) Testing

To verify the RTC functionality on reComputer R1100, follow these steps:

Disable Automatic Time Synchronization

Before testing the RTC, stop and disable automatic time sync to avoid conflicts:

sudo systemctl stop systemd-timesyncd  
sudo systemctl disable systemd-timesyncd  

Manually Set the RTC Time

Set the RTC to a specific date and time (e.g., November 12, 2024, at 12:00 PM):

sudo hwclock --set --date "2024-11-12 12:00:00"

Sync RTC Time to the System

Update the system time to match the RTC time:

sudo hwclock --hctosys

Verify the RTC Time
Check the current time stored in the RTC:

sudo hwclock -r

This command will display the RTC time.

Test RTC Retention

• Disconnect the power source from the RTC.
• Wait a few minutes.
• Reconnect the power and check the RTC time again using:

  sudo hwclock -r
• If the time remains correct, the RTC is functioning properly.

Watchdog Timer Testing

To test the watchdog timer on reComputer R1100, follow these steps:

Install Watchdog Software

Ensure the watchdog package is installed:

sudo apt install watchdog

Configure the Watchdog

Edit the watchdog configuration file:

sudo apt-get install vim  # Install Vim if not already installed  
sudo vim /etc/watchdog.conf

Modify the configuration as follows:

watchdog-device = /dev/watchdog  

# Set the hardware timeout (default is 1 minute)
watchdog-timeout = 120  

# Set the interval between tests (should be shorter than watchdog-timeout)
interval = 15  

# Set system load limits  
max-load-1 = 24  
# max-load-5 = 18  
# max-load-15 = 12  

# Enable real-time priority  
realtime = yes  
priority = 1  

Start the Watchdog Service
Enable and start the watchdog service:

sudo systemctl start watchdog

Test the Watchdog by Simulating a System Hang

Trigger a kernel crash to see if the watchdog automatically reboots the system:

sudo su
echo 1 > /proc/sys/kernel/sysrq
echo "c" > /proc/sysrq-trigger

Monitor the System
Check if the system automatically reboots after the specified timeout period.

If the reboot occurs as expected, the watchdog is functioning properly.

Controlling the Buzzer via GPIO

The buzzer is mapped to GPIO 587. Use the following commands to turn it on and off:

Turn on the buzzer:

echo 587 > /sys/class/gpio/export  
echo out > /sys/class/gpio/gpio587/direction  
echo 1 > /sys/class/gpio/gpio587/value  

Turn off the buzzer:

echo 587 > /sys/class/gpio/export  
echo out > /sys/class/gpio/gpio587/direction  
echo 0 > /sys/class/gpio/gpio587/value  

CSI Camera Testing

To test the CSI camera on reComputer R1100, follow these steps:

Modify the Configuration File

Edit the config.txt file to enable the camera module:

sudo nano /boot/firmware/config.txt

Add the following line at the end of the file:

dtoverlay=imx219,cam0

Restart the System

Reboot to apply the changes:

sudo reboot

Check Camera Detection

After restarting, verify if the camera is detected:

libcamera-jpeg --list-cameras

---

Test the Camera

Run the following command to activate the camera:

rpicam-hello --timeout 0

If the camera preview starts successfully, the setup is complete!

TPM 2.0 Connection Check

If you have connected a TPM 2.0 module to your device, you can verify its detection using the following command:

ls /dev | grep tpm

Interpreting the Output:

• If you see tpm0 and tpmrm0 in the output, it confirms that the TPM (Trusted Platform Module) is successfully detected and available.
• This indicates that the TPM hardware is recognized and accessible, allowing you to proceed with TPM-related functionalities or applications.

If the devices are listed, your TPM module is properly connected and ready for use.

Interacting with ATECC608A and Generating a Random Serial Number

To communicate with the ATECC608A device and generate a random serial number, follow these steps:

Clone the atecc-util Repository:

git clone https://github.com/wirenboard/atecc-util.git

Navigate to the atecc-util Directory:

cd atecc-util

Clone the cryptoauthlib Repository:

git clone https://github.com/wirenboard/cryptoauthlib.git

Compile the ATECC Utility:

make

Generate a Random Serial Number:

./atecc -b 1 -s 192 -c 'serial'

• -b 1 → Uses slot 1.
• -s 192 → Sets the serial number size to 192 bits.
• -c 'serial' → Generates a random serial number.

Expected Output:

The generated serial number will be displayed, for example:

01235595d3d621f0ee

This method enables interaction with the ATECC608A device, allowing you to perform operations like generating random serial numbers efficiently.

Interacting with EEPROM

To read and write data to an EEPROM (Electrically Erasable Programmable Read-Only Memory), follow these steps:

Grant Full Permissions to the EEPROM Device File:

sudo chmod 777 /sys/bus/i2c/devices/6-0050/eeprom

Write Data to the EEPROM:

echo "This is a test string" > /sys/bus/i2c/devices/6-0050/eeprom

Read the EEPROM Contents in Hexadecimal Format:

cat /sys/bus/i2c/devices/6-0050/eeprom | hexdump -C

Checking SSD Detection

To list all connected disks, including the SSD, use the following command:

sudo fdisk -l

This command will display a list of all detected storage devices. Look for entries that represent your SSD, typically labeled as:

• /dev/sda
• /dev/sdb
• /dev/sdc, etc.

Once you identify the correct SSD entry, you can proceed with partitioning, formatting, or other disk management tasks as needed.

UPS for Safe Shutdown

A GPIO6 connection between the CPU and DC power-in is used to notify the CPU when the power supply is down. The CPU must execute urgent tasks via a script before the supercapacitor’s energy is depleted and then initiate a safe shutdown ($shutdown).

Alternative Shutdown Method
Another way to use this function is to trigger a shutdown when the GPIO pin changes state. The specified GPIO pin is configured as an input key, generating KEY_POWER events. These events are handled by systemd-logind, which automatically initiates a system shutdown.

To enable this function, refer to /boot/overlays/README, then modify /boot/firmware/config.txt by adding:

dtoverlay=gpio-shutdown,gpio_pin=6,active_low=1

note

1. For UPS functionality details, please contact us.
2. The alarm signal is active LOW.

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Python Code for Safe Shutdown

The following Python script demonstrates how to detect the working mode of the supercapacitor UPS via GPIO6. When the system detects a power-off event, it automatically saves data and shuts down safely.

import RPi.GPIO as GPIO
import time
import os

num = 0

GPIO.setmode(GPIO.BCM)  # Set GPIO numbering mode
GPIO.setup(6, GPIO.IN, pull_up_down=GPIO.PUD_UP)  # Set GPIO6 as input with pull-up resistor
GPIO.add_event_detect(6, GPIO.FALLING, bouncetime=500)  # Add debounce time for stabilization

while True:
    if GPIO.event_detected(6):
        print("...External power off detected...")
        os.system("sync")  # Ensure data is written to disk
        print("...Saving data...")
        time.sleep(3)
        os.system("sync")  # Save data again
        
        while num < 5:
            print(f"--- {5 - num} seconds remaining ---")
            num += 1
            time.sleep(1)

        os.system("sudo shutdown -h now")  # Execute system shutdown

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